CVE-2024-34704: era-compiler-solidity contains a `xor(zext(cmp), -1)` misoptimization

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-14 · updated 2026-06-17
Weakness: CWE-682

Description

era-compiler-solidity is the ZKsync compiler for Solidity. The problem occurred during instruction selection in the `DAGCombine` phase while visiting the XOR operation. The issue arises when attempting to fold the expression `!(x cc y)` into `(x !cc y)`. To perform this transformation, the second operand of XOR should be a constant representing the true value. However, it was incorrectly assumed that -1 represents the true value, when in fact, 1 is the correct representation, so this transformation for this case should be skipped. This vulnerability is fixed in 1.4.1.

Affected products

matter-labs era-compiler-solidity: from 1.2.0 before 1.4.1 — fixed in 1.4.1

How to fix

Upgrade to a fixed version: matter-labs era-compiler-solidity 1.4.1. Check the vendor advisory for mitigations.

References

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